Boiler-tube fastening.



PATENTED MAR. '7, 1905.

C. E. THROOP.

BUILER TUBE PASTBNING.

APPLICATION FILED MAE. 23, 1903.

vllillll` ...1,

ivo. 784,192.

-NTTED STaTns Patented March 7, 1905,.

CHARLES E. THROOP, 0F BUFFALO, NFV YURK.

BOlLER-'TUEE FASTENlNG.

SPECIFICATION forming part of Letters Patent No. 74=,192, dated March '7, 1905.

Application tiled March 2S, 1903. Ecrial No. 149,145.

To /LZZ 1071/0711, 'ift may concern.-

Be it known that I, CHARLES E. Tuuoor, a citizen ol the United States, residing' at Buffalo, in the county of Erie and State ol: New York, have invented new and useful Im provements in Boiler-Tube Fastenings, oi" which the following is a specification.

This invention relates to a boiler-tube fastening, and has the object to provide a `fastening for this purpose which produces a tight joint between the tube and tube-sheet, which permits the tube to expand lengthwise without liability oi cracking or breaking, and which enables the tube to be readily and conveniently secured to the tube-sheet or replaced by another when necessary.

In the accompanying drawings, Figure l is a sectional elevation ot' a boiler having its tubes and sheets connected by my improved fastening, the manner ot' securing a tube in a sheet, removing a tube from a sheet, and plugging a leaky tube being shown on different tubes. Fig. Q is a `llagmentary top plan View of the same. Fig. 3 is a fragmentary vertical section, on an enlarged scale, of the 'fastening whereby the tube is secured in the sheet, showing the tube expanded lengthwise.

Similar letters of reference indicate corresponding parts throughout the several views.

A represents the cylindrical shell or body of the boiler, B B the flat heads or sheets applied to opposite ends thereof, and C the lues or tubes which are secured at opposite ends to said sheets. Inasmuch as the means for supplying water to the interior of the boiler and conducting the steam therefron'l and the means for heating the interior oi the tubes forms no part of my invention and may be effected in any suitable manner, no means are shown for performing these functions.

Each ot' the heads or sheets is provided with a plurality of seats or openings D oi cylindrical form on its inner surface and a plurality of circular sockets E on its outer side, which are axially in line with the openings. The sockets are enlarged or oi greater diameter than the openings, so as to Vlorm an outwardly-facing annular shoulder j' on the sheet between the inner opposing ends olI each companion opening' and socket. Flach end ol a tube lits into an opening ol a sheet and is provided with an external [lange y, which bears on its inner side against a shoulder j' el the sheet.

lilV represents clamping-rings Alor securing the ends ot' the tubes in the sheets. lilach olA the rings bears on its iimersideor end agaii'ist the outer side of the tube-flange and is secured in the socket by external screw-threaul /1/ on its periphery engaging with an internal screwthread a in the bore ol" the socket.

Preparatory to placing a tube in the boiler one end o'l the tube is provided with an external annular flange, while the other end or' the tube is lcit in a straight unl'langed condition. This tube is then passed, with its unilanged end `foremost, through a corresponding` pair of openings in both heads or sheets until the iiange at one end bears against the shoulderf on one sheet, as shown at u', while the other uniianged end projects outwardly beyond the adjacent shoulder el.g the othersheet, as shown at rf. The flanged end of the tube is now tightly secured to its sheet by screwing a clam pi ng-ring H into the corresponding socket until the adjacent flange oi the tube is pressed between the shoulder et the respective socket and the inner side ot' the clam ping-ring suliiciently iirni to prevent leakage between the same. The opposite straight end olI the tube is then provided with an external annular llange, which latter is engaged with the shoulder in the respective socket ol. the adjacent sheet. The last-mentioned flange is formed in the tube while the same is seated in both sheets, and the 'Hangingoperation is preferably etiected in two successive steps by two tools J K. 'lhe lirst er starting tool J consists oi a shank or body j,

having a reduced mandrel y" at one end and a rounded shoulder j between the mandrel and body of comparatively large radius. Upon inserting theu mandrel ot' the starting-tool into the straight end ol the tube and then driving this tool inwardly so that its shoulder engages` the tube the straight end ol the latter will be swaged out\vardly and the annular flange partially formed thereon, as shown at Z. The starting-tool is then replaced by the second or finishing tool K, which latter has a body and a reduced mandrel fg; but the shoulderlt'3 at the junction of its body and mandrel is rounded more abrupt or on a smaller' radius than the starting-tool, which causes this tool when driven into the partially-flanged end of the tube to complete the external flange on the same and force this flange firmly against the shoulder of its socket, as shown at m. The finishing-tool is next withdrawn, and aclamping-ringl is lirml y screwed into the respective socket and against the flange of the tube therein for producing a tight joint between this end of the tube and its tube-sheet.

If desired, the use of the finishing-tool K may be omitted, and the final bending' of the tube-flange may be effected by the clampingring vas the same is screwed into the socket and against the flange.

In order to permit the clamping-rings to be easily screwed into and out of the sockets, the

'same may be constructed for receiving a wrench of any suitable kind. I prefer for this purpose to make the interior of the clamping-rings hexagonal, whereby the same may receive a wrench of corresponding form for turning the ring.

It has been found in practice'that when the flange of the tube is clamped its full width between the shoulder of the tube-sheet and the clamping-ring the longitudinal movement or expansion of the tube, due to variation in temperature, is liable to produce a crack or break in the tube at the junction of the body and flange, resulting in leakage. In order to avoid this difficulty, the clamping-ring is so constructed that the diameter of its bore is substantially the same as the exterior of the tube, as shown in Fig. 3, and the shoulder of the tube-sheet and the inner end or side of the clamping-ring are constructed so that the space between them which receives the flange flares inwardly. This causes the flange to be clamped only at its outermost part or margin between the shoulder and ring, leaving that part of the flange next to the cylindrical body of the tube free to move lengthwise with the same, as indicated in Fig. 3, thereby avoiding an abrupt bend in the flange and preventing cracking' of the same. This inwardly-flaring formation of the space which receives the tube-flange is preferably produced by convexly rounding the tube-sheet at the junction of its shoulder and the tube-opening', as shown at a, and by convexly rounding the clamping-ring at the junction of its inner side and its bore, as shown at o.

Then a tube leaks and it becomes necessary to remove the same, this can be quickly and easily done by removing' the clal'nping-rings at both ends of the tube and then driving' a cutting-tool P into one end of the tube. This tool has a body which fits into the tube-opening and a reduced mandrel p, which fits into the tube and is joined with the body by a sharp or angular shoulder p, which forms a cutting edge. Upon driving this tool into the tube its shoulder p severs the flange from the body of the tube, leaving the flange resting on the shoulder of the tube-sheet, as shown at q, while the body of the tube is moved lengthwise, whereby its unflanged end is removed from its tube-sheet and its opposite end is pushed out of its socket, as shown at Q', so that its flange is accessible and permits the tube to be withdrawn from the boiler.

My improved boiler-tube fastening is particularly desirable for steam-boilers used in motor-vehicles,which boilers are liable to burn out when the water-supply is insuflicient and render the machine inoperative. If an accident of this kind should occur to the boiler while out on a trip, the leaky tube can be easily replaced by a new one, of which a supply may be kept on hand, thereby avoiding the annoyance of a lengthy delay or possible abandonment of the trip.

Instead of replacing a leaky tube while on the road with the motor-vehicle the defective tube may be put out of service for the time being by .plugging or closing the opposite ends of the tube. This may be done by replacing the clamping-ring with a solid or imperforatc screw-plug 7*, as shown at the upper end of one of the tubes in Fig. 1, or a solid washer or disk r may be secured against the flanged end of the tube by the clamping-ring, as shown at the lower end of the same tube in Fig. l. The removal of the faulty tube by this means can be deferred until the journey is ended or until a more opportune time.

In order to prevent the clamping-rings from sticking, the screw-joints between the same and the tube-sheets are preferably coated with black-lead, as this avoids burning the rings so firmly in their sockets as to render their removal difficult.

I claim as my invention4 A boiler-tube fastening comprising a tubesheet provided with a tube-opening' which has a narrow inner portion and an enlarged outer portion forming an outwardly-facing shoulder between the same, the inner portion of said opening being plain while the outer portion has an internal screw-thread, a tube arranged in said opening and provided at its outer end with an external annular flange which is arranged in the enlarged portion of said opening, and bears on its inner side against said flange, a clamping-ring bearing against the outer side of said flange and having an external screw-th read which engages with the internal thread of the outer portion of said opening, the bore of said clamping-ring being of substantially the same diameter as the exterior of said tube and the inner edge of said IOO IIO

shoulder and the opposing inner edge of the I VitneSs my hand this 20th day of March, clampingring being rounded causing the 1903.

flange to be gripped only at its outer part or l edge leaving its inner part or base free to move lengthwise with the tube during the expeni sion and contraction of the same, Substantially :is set forth.

CHARLES E. THROOP.

VVitnesseS:

Timo. L. Pori, EMMA M. G'nAHAivi. 

